Wataru Sato and others at Kyoto University have discovered why you're so unhappy: your precuneus is too small. Definitively we've found where some of the "happiness" is generated in the brain, and it's in the precuneus. People with more gray matter there are happier. People with less gray matter there are less happy and arguably less capable of happiness.
The good news is that mindfulness does increase the amount of gray matter in the precuneus:
If you are having a hard time firing up your happiness, growing more gray matter in the precuneus will help. Ensure you have some mindfulness time built into your daily practice.
What else can you do if your precuneus is undersized? Additional happiness builders are exercise, gratitude and forgiveness.
Repeatedly, exercise has been shown to be as or more effective at curing major clinical depression than drug therapies:
Hostility is known to depress serotonin and dopamine, shortening lifespan and reducing the capacity for happiness: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2077351/. Johns Hopkins has a great page about the power of forgiveness with respect to completely healing PTSD, severe depression, and the prevention of heart disease and stroke:
Thus, a countering practice of gratefulness and forgiveness along with mindfulness and exercise can provide paths to greater overall wellbeing, even if you start with a too-tiny precuneus.
To learn more about how to improve mood, raise motivation and the like, click here.